1. Technical Field
The present invention relates to a device for mixing medical fluids, wherein the mixing device has an inlet port for receiving at least a first medical fluid, an injection port for injection of a second medical fluid, an outlet port for exit of a mixed flow of the first and second medical fluids, a first duct extending between the injection port and the inlet port, and a second duct extending between the inlet port and the outlet port, where the injection port is sealed by a fluid-proof membrane that can be penetrated by an injection needle when injecting the second medical fluid. The invention further relates to a method for enabling mixing of medical fluids by means of the device.
2. Background Information
A serious problem in connection with drug preparation, drug administration, and other similar handling is the risk that medical and pharmacological staff are exposed to drugs or solvents which might escape into the ambient air. This problem is particularly serious where the preparation of cytotoxins, antiviral drugs, antibiotics and radiopharmaceuticals are concerned. For this reason, there has been a need for safer systems for handling and administrating drugs and other medical substances.
Accordingly, U.S. Pat. No. 4,564,054 to Gustavsson (“the '054 patent”) discloses a fluid transfer device for transferring a substance from one vessel to another vessel while avoiding leakage of liquid and gas contaminants. The disclosed device includes a first member designed as a hollow sleeve and having a piercing member provided with a passageway. The piercing member is attached to the first member, which has a first barrier member at one end just opposite the tip of the piercing member. As such, the piercing member can be passed and retracted through the first barrier member that seals one end of the first member.
The fluid transfer device further includes a second member which is attached to or attachable to one of the vessels or to means arranged to communicate therewith. The second member has a second barrier member and mating connector or connection means arranged on the first and second members for providing a releasable locking of the members with respect to each other. The barrier members are liquid and gas-proof sealing members which seal tightly after penetration and retraction of the piercing member, and prevent leakage of liquid as well as gas contaminants. In the connected position of the first and second members, the barrier members are located so that the piercing member can pass there through.
According to the '054 patent, the above-mentioned piercing member is a needle arranged for puncturing the first and the second barrier members, wherein the end opposite the one end of the first member has means for sealingly receiving or being permanently attached to an injection syringe or the like for withdrawing and/or adding substance to the vessel attached to the second member. When attached to the first member, the injection syringe or the like communicates with the passageway of the needle so that, in the retracted position, the needle is hermetically enclosed in the first member having the injection syringe or the like connected thereto.
Furthermore, International Patent Publication No. WO 99/27886 to Fowles et al. (“the '886 publication”) discloses a connector device intended for establishing fluid communication between a first container and a second container. The connector device has a first sleeve member having a first and a second end. The first sleeve member has a first attaching member at the first end which is adapted to attach to the first container. The connector device further includes a second sleeve member that has a first end and a second end. The second sleeve member is associated to the first sleeve member and movable with respect thereto from an inactivated position to an activated position. The second sleeve member has a second attaching member at the second end adapted to attach the second sleeve member to the second container. According to the '886 publication, the connector device also includes a first and second piercing member projecting from one of the first and second sleeve members for providing a fluid flow path from the first container to the second container, and means for independently hermetically sealing the first and second members.
The administration of medical fluids to a patient can be accomplished by inserting a catheter into a patient's vein, and then coupling a source of medical fluid thereto using an administration set that may include flexible tubing and one or more injection sites. A typical gravity feeding system for infusion therapy includes a container, e.g., a plastic bag, for the parental solution, a tube extending from the bag and connected to a Y-injection site, and a tube from the Y-Injection site to a needle or catheter which is inserted into a vein of the patient.
Typically, the infusion fluid line is connected to the infusion bag by a spike device. In this well known system, a rigid spike member penetrates a septum sealing a fluid transfer port of the infusion bag, thereby establishing fluid communication between the infusion bag and the infusion line on which one or several injection sites or ports can be provided. Thereby, the injection of a drug into the infusion fluid is normally accomplished by penetrating a septum that seals the injection port using a conventional hypodermic needle. However, this solution has not been satisfactory from a safety point of view, since it involves a substantial risk of health-hazardous substances escaping into the environment.
For this reason, there is a need for safer devices for introducing a drug or another medical substance into an infusion fluid of an infusion system.
A number of alternative solutions for introducing a medical substance into an infusion system have been proposed, such as those disclosed in U.S. Pat. No. 6,245,056 to Walker et al., U.S. Pat. No. 6,113,068 to Ryan, U.S. Pat. No. 6,221,065 to Davis, U.S. Pat. No. 6,146,362 to Turnbull et al. and U.S. Pat. No. 4,878,897 to Katzin.
Furthermore, International Patent Publication WO 98/19724 to Wessman discloses an improved device for administrating a toxic fluid. The device includes an infusion device for connection to an infusion bag, and is provided with an insertion portion for connecting the bag, and an infusion chamber for dosing a fluid flow via a flow duct in the insertion portion from the bag to an outlet arranged on the chamber. The insertion portion also includes a ventilating duct that extends between the bag and the outside of the infusion device, ending in a connection arranged on the side of the infusion device for supplying the fluid to be administrated, wherein the connection is provided with at least one membrane which is air tight and penetrable by an injection needle.
Several of the solutions disclosed in the above-mentioned documents allow the safe introduction of a potentially health-hazardous medical substance into an infusion system. However, the previously proposed solutions utilize devices assembled from a large number of components, and therefore are also expensive to manufacture.
Another drawback of those devices is the use of glue or adhesive connections between the different components in order to establish a fluid communication between an infusion fluid container and an infusion line connected to a patient. The extensive use of glue or adhesive for these connections is a disadvantage, since it creates problems with the working environment in the manufacturing plant and also increases the manufacturing cost.